Substrate Processing Method and Substrate Processing Apparatus

This application is a continuation application of PCT Application No. PCT/JP2023/045771, filed on Dec. 20, 2023, which claims the benefit of priority from Japanese Patent Application No. 2022-211966, filed on Dec. 28, 2022. The entire contents of the above listed PCT and priority applications are incorporated herein by reference.

The present disclosure relates to a substrate processing method and a substrate processing apparatus.

Japanese Unexamined Patent Application Publication No. 2000-12515 discloses a substrate processing method and a substrate processing apparatus capable of suppressing damage to a chamber or a component.

Disclosed herein is a substrate processing method. The substrate processing method may include (a) providing a substrate on a substrate support in a chamber, the substrate including an etching target film and a metal-containing resist on the etching target film, the metal-containing resist including a first region exposed to EUV light and a second region not exposed to the EUV light, (b) removing the second region by dry development using a development gas, and (c) removing a first metal-containing substance adhered to the chamber or a component disposed in the chamber after the (b), in which the (c) includes (c1) generating a second metal-containing substance from the first metal-containing substance using a fluorine-containing gas, the second metal-containing substance including a metal fluoride, and (c2) generating a third metal-containing substance from the second metal-containing substance and removing the third metal-containing substance by heating the chamber or the component and supplying a processing gas into the chamber.

In the following description, with reference to the drawings, the same reference numbers are assigned to the same components or to similar components having the same function, and overlapping description is omitted.

is a diagram for describing a configuration example of a heat treatment system. In one exemplary embodiment, a heat treatment system includes a heat treatment apparatusand a controller. The heat treatment system is an example of a system for processing a substrate. The heat treatment apparatusis an example of a substrate processing apparatus.

The heat treatment apparatushas a processing chamber(chamber) that is configured to be sealable. The processing chamberis, for example, an airtight cylindrical container, and is configured to be able to control the atmosphere inside. A side wall heateris provided on a side wall of the processing chamber. A ceiling heateris provided on a ceiling wall (top plate) of the processing chamber. A ceiling surfaceof a ceiling wall (top plate) of the processing chamberis formed as a horizontal flat surface, for example. A temperature of the ceiling surfaceis controlled by the ceiling heater.

A substrate supportis provided on a lower side in the processing chamber. The substrate supportconstitutes a placing portion on which a substrate W is placed. The substrate supportmay have, for example, a circular surface (upper surface) or may have a surface (upper surface) formed horizontally. The substrate W is placed on a surface of the substrate support. A stage heateris embedded in the substrate support. The stage heatercan heat the substrate W placed on the substrate support. A ring assemblymay be disposed on the substrate supportto surround the substrate W. The ring assemblymay include one or a plurality of annular members. By disposing the ring assembly, it is possible to improve the temperature controllability of an outer peripheral region of the substrate W. The ring assemblymay be made of inorganic materials or organic materials depending on the desired heat treatment.

The substrate supportis supported in the processing chamberby a columnprovided on a bottom surface of the processing chamber. A plurality of lift pinsthat, for example, vertically move are provided on an outer side of the columnin a circumferential direction. The plurality of lift pinsare each inserted into a plurality of through-holes provided at intervals in the circumferential direction of the substrate support. The lifting operation of the lift pinis controlled by a lift mechanism. In a case where the lift pinprotrudes from the surface of the substrate support, the substrate W is delivered between a transport mechanism (not shown) and the substrate support.

An exhaust porthaving an opening is provided on a side wall of the processing chamber. The exhaust portis connected to an exhaust mechanismvia an exhaust pipe. The exhaust mechanismis made of a vacuum pump, a valve, and the like, and adjusts an exhaust flow rate from the exhaust port. The pressure in the processing chamberis adjusted by adjusting the exhaust flow rate and the like by means of the exhaust mechanism. A transport port (not shown) of the substrate W is formed to be openable and closable, on a side wall of the processing chamberat a position different from a position of the exhaust port.

In addition, a gas nozzleis provided at a position different from the positions of the exhaust portand the transport port of the substrate W on the side wall of the processing chamber. The gas nozzlesupplies the processing gas into the processing chamber. The gas nozzleis provided on a side opposite to the exhaust portas viewed from a central portion of the substrate support, on the side wall of the processing chamber.

The gas nozzleis formed in a rod shape that protrudes from the side wall of the processing chambertoward the center side of the processing chamber. A distal end of the gas nozzleextends, for example, horizontally from the side wall of the processing chamber. The processing gas is discharged into the processing chamberfrom a discharge port provided at the distal end of the gas nozzle. The discharged processing gas flows in a direction of an arrow shown inand is discharged from the exhaust port. The distal end of the gas nozzlemay extend obliquely downward toward the substrate W, or may extend obliquely upward toward the ceiling surfaceof the processing chamber.

The gas nozzlemay be provided, for example, on the ceiling wall of the processing chamber. The exhaust portmay be provided on the bottom surface of the processing chamber.

The heat treatment apparatushas a gas supply pipeconnected to the gas nozzlefrom the outer side of the processing chamber. A pipe heaterfor heating an inside of the gas supply pipeis provided around the gas supply pipe. The gas supply pipeis connected to a gas supply. The gas supplyincludes at least one gas source and at least one flow rate control device. The gas supply may include a vaporizer that vaporizes a gas source in a liquid state.

The controllerprocesses computer-executable instructions for causing the heat treatment apparatusto execute various steps described in the present disclosure. The controllermay be configured to control each element of the heat treatment apparatusto execute various steps described herein. In one embodiment, a part or all of the controllermay be included in the heat treatment apparatus. The controllermay include a processor, a storage, and a communication interface. The controlleris realized by, for example, a computerThe processorcan be configured to read out a program from the storageand execute the read out program to perform various control operations. This program may be stored in the storagein advance, or may be acquired via the medium when necessary. The acquired program is stored in the storage, and is read out from the storageand executed by the processor. The medium may be various storage media readable by the computeror may be a communication line connected to the communication interface. The processormay be a central processing unit (CPU). The storagemay include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or combinations thereof. The communication interfacemay be communicated with the heat treatment apparatusvia a communication line such as a local area network (LAN).

is a schematic diagram showing a substrate processing apparatus according to another exemplary embodiment. A heat treatment apparatusshown infurther includes a microwave heating devicein addition to the configuration of the heat treatment apparatusshown in. The microwave heating devicecan heat the processing chamberor a component (for example, the substrate supportand the ring assembly) disposed in the processing chamber.

The microwave heating devicemay include a microwave generator, a waveguide, and a quartz window. The microwave generatoris provided outside the processing chamber, for example, above the processing chamber. The microwave generatorincludes a magnetron and generates a microwave. A frequency of the microwave is, for example, 2.45 GHz or 5.85 GHz. One end of the waveguideis connected to the microwave generator. The other end of the waveguideis connected to the quartz window. The quartz windowhas a first surface connected to the waveguideof the quartz windowand a second surface on a side opposite to the first surface. The quartz windowis provided such that the second surface is flush with the ceiling surfaceof the processing chamber. The microwaves generated in the microwave generatorare emitted toward the processing chamberor the substrate supportthrough the waveguideand the quartz window. As a result, an inner surface of the processing chamberor a surface of the substrate supportis heated. The irradiation direction of the microwave can be adjusted by positions or orientations of the waveguideand the quartz window.

The microwave heating devicemay heat the processing chamberor the substrate supportby generating electromagnetic waves (for example, infrared rays) different from the microwaves. The microwave heating devicemay include an infrared lamp. The heat treatment apparatusmay include at least one of the side wall heater, the stage heater, the ceiling heater, and the pipe heater. Alternatively, the heat treatment apparatusmay not include these heaters.

is a diagram for describing a configuration example in a case where the plasma processing system is used as the development processing system. In one embodiment, a plasma processing system includes a plasma processing apparatusand a controller. The plasma processing system is an example of a system for processing a substrate, and the plasma processing apparatusis an example of a substrate processing apparatus. The plasma processing apparatusincludes a plasma processing chamber (hereinafter, also simply referred to as a “processing chamber”), a substrate support, and a plasma generator. The plasma processing chamberhas a plasma processing space. In addition, the plasma processing chamberhas at least one gas supply port for supplying at least one processing gas into the plasma processing space and at least one gas exhaust port for exhausting gases from the plasma processing space. The gas supply port is connected to a gas supplydescribed below and the gas exhaust port is connected to an exhaust systemdescribed below. The substrate supportis disposed in the plasma processing space and has a substrate supporting surface for supporting the substrate.

The plasma generatoris configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance (ECR) plasma, a helicon wave plasma (HWP), or a surface wave plasma (SWP), or the like. In addition, various types of plasma generators including an alternating current (AC) plasma generator and a direct current (DC) plasma generator may be used. In one embodiment, an AC signal (AC power) used in the AC plasma generator has a frequency in a range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in a range of 100 kHz to 150 MHz.

The controllerprocesses computer-executable instructions for causing the plasma processing apparatusto execute various steps described in the present disclosure. The controllermay be configured to control each element of the plasma processing apparatusto execute various steps described herein. In one embodiment, the functions of the controllermay be partially or entirely incorporated into the plasma processing apparatus. The controlleris realized by, for example, a computerThe controllermay include a processor, a storage, and a communication interface. Each configuration of the controllermay be the same as each configuration of the controllerdescribed above (see).

In the following, a configuration example of a capacitively coupled plasma processing apparatus, which is an example of the plasma processing apparatus, will be described.is a diagram for describing a configuration example of a capacitively coupled plasma processing apparatus.

The capacitively coupled plasma processing apparatusincludes the plasma processing chamber, the gas supply, a power supply, and an exhaust system. In addition, the plasma processing apparatusincludes a substrate supportand a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber. The gas introduction unit includes a shower head. The substrate supportis disposed in the plasma processing chamber. The shower headis disposed above the substrate support. In one embodiment, the shower headconstitutes at least a part of the ceiling of the plasma processing chamber. The plasma processing chamberhas a plasma processing spacethat is defined by the shower head, a side wallof the plasma processing chamber, and the substrate support. The plasma processing chamberis grounded. The shower headand the substrate supportare electrically insulated from a housing of the plasma processing chamber.

The substrate supportincludes a bodyand a ring assembly. The bodyhas a central regionfor supporting the substrate W and an annular regionfor supporting the ring assembly. A wafer is an example of the substrate W. The annular regionof the bodysurrounds the central regionof the bodyin a plan view. The substrate W is disposed on the central regionof the body, and the ring assemblyis disposed on the annular regionof the bodyto surround the substrate W on the central regionof the body. Thus, the central regionis also referred to as a substrate supporting surface for supporting the substrate W, while the annular regionis also referred to as a ring supporting surface for supporting the ring assembly.

In one embodiment, the bodyincludes a baseand an electrostatic chuck. The baseincludes a conductive member. The conductive member of the basecan function as a lower electrode. The electrostatic chuckis disposed on the base. The electrostatic chuckincludes a ceramic memberand an electrostatic electrodedisposed in the ceramic memberThe ceramic memberhas the central regionIn one embodiment, the ceramic memberalso has the annular regionIn addition, other members surrounding the electrostatic chuck, such as an annular electrostatic chuck or an annular insulating member, may have the annular regionIn this case, the ring assemblymay be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuckand the annular insulating member. In addition, at least one RF/DC electrode coupled to an RF power supplyand/or a DC power supplydescribed below may be disposed in the ceramic memberIn this case, at least one RF/DC electrode functions as the lower electrode. In a case where a bias RF signal and/or a DC signal described below is supplied to at least one RF/DC electrode, the RF/DC electrode is also referred to as a bias electrode. The conductive member of the baseand at least one RF/DC electrode may function as a plurality of lower electrodes. In addition, the electrostatic electrodemay function as the lower electrode. Therefore, the substrate supportincludes at least one lower electrode.

The ring assemblyincludes one or a plurality of annular members. In one embodiment, the one or plurality of annular members include one or a plurality of edge rings and at least one cover ring. The edge ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

In addition, the substrate supportmay include a temperature adjusting module that is configured to adjust at least one of the electrostatic chuck, the ring assembly, and the substrate to a target temperature. The temperature adjusting module may include a heater, a heat transfer medium, a flow pathor any combination thereof. A heat transfer fluid, such as brine or gas, flows into the flow pathIn one embodiment, the flow pathis formed in the base, and one or a plurality of heaters are disposed in the ceramic memberof the electrostatic chuck. In addition, the substrate supportmay further include a heat transfer gas supply configured to supply a heat transfer gas to a gap between a back surface of the substrate W and the central region

The shower headis configured to introduce at least one processing gas from the gas supplyinto the plasma processing spaceThe shower headhas at least one gas supply portat least one gas diffusion chamberand a plurality of gas introduction portsThe processing gas supplied to the gas supply portpasses through the gas diffusion chamberand is introduced into the plasma processing spacefrom the plurality of gas introduction portsIn addition, the shower headincludes at least one upper electrode. The gas introduction unit may include one or a plurality of side gas injectors (SG) attached to one or a plurality of openings formed in the side wallin addition to the shower head.

The gas supplymay include at least one gas sourceand at least one flow rate control device. In one embodiment, the gas supplyis configured to supply at least one processing gas from the respective corresponding gas sourcethrough the respective corresponding flow rate control deviceto the shower head. Each flow rate control devicemay include, for example, a mass flow controller or a pressure-controlled flow rate control device. Further, the gas supplymay include at least one flow rate modulation device that modulates or pulses the flow rate of at least one processing gas.

The power supplyincludes the RF power supply, which is coupled to the plasma processing chambervia at least one impedance matching circuit. The RF power supplyis configured to supply at least one RF signal (RF power) to at least one lower electrode and/or at least one upper electrode. As a result, plasma is formed from at least one processing gas supplied to the plasma processing spaceTherefore, the RF power supplycan function as at least a part of the plasma generator. In addition, by supplying the bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ion components in the formed plasma can be drawn into the substrate W.

In one embodiment, the RF power supplyincludes a first RF generatorand a second RF generatorThe first RF generatoris configured to be coupled to at least one lower electrode and/or at least one upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in a range of 10 MHz to 150 MHz. In one embodiment, the first RF generatormay be configured to generate a plurality of source RF signals having different frequencies. The generated one or plurality of source RF signals are supplied to at least one lower electrode and/or at least one upper electrode.

The second RF generatoris configured to be coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in a range of 100 kHz to 60 MHz. In one embodiment, the second RF generatormay be configured to generate a plurality of bias RF signals having different frequencies. The generated one or plurality of bias RF signals are supplied to at least one lower electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

In addition, the power supplymay include the DC power supplycoupled to the plasma processing chamber. The DC power supplyincludes a first DC generatorand a second DC generatorIn one embodiment, the first DC generatoris configured to be connected to at least one lower electrode and is configured to generate a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generatoris configured to be connected to at least one upper electrode and is configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of the voltage pulses is applied to at least one lower electrode and/or at least one upper electrode. The voltage pulse may have a pulse waveform of a rectangular, trapezoidal, triangular, or a combination thereof. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generatorand at least one lower electrode. Therefore, the first DC generatorand the waveform generator constitute a voltage pulse generator. In a case where the second DC generatorand the waveform generator constitute the voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulse may have a positive polarity or may have a negative polarity. Further, the sequence of the voltage pulses may include one or a plurality of positive-polarity voltage pulses and one or a plurality of negative-polarity voltage pulses in one cycle. The first and second DC generatorsandmay be provided in addition to the RF power supply, or the first DC generatormay be provided instead of the second RF generator

The exhaust systemmay be connected to, for example, a gas exhaust portprovided in a bottom of the plasma processing chamber. The exhaust systemmay include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing spaceis adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

is a flowchart of a substrate processing method (hereinafter, referred to as a “method MT”) according to one exemplary embodiment. The method MTmay include Step STto Step ST. Step STto Step STmay be executed in order. The method MTmay not include Step STto Step STand Step ST.

The method MTmay be executed by using any one of the systems for processing a substrate described above (see), or may be executed by using two or more of these systems for processing a substrate. For example, the method MTmay be executed using the heat treatment system (seeor). In the following, a case where the controllercontrols each unit of the heat treatment apparatusor the heat treatment apparatusto execute the method MTon a first substrate W(see) and a second substrate W(see) will be described as an example.

is a view showing an example of a cross-sectional structure of the first substrate Wprovided in Step ST. The first substrate Wincludes an underlying film UF, an etching target film FL formed on the underlying film UF, and a metal-containing resist RM. The first substrate Wmay be used for manufacturing a semiconductor device. The semiconductor device includes, for example, a semiconductor memory device such as a DRAM or a 3D-NAND flash memory. The etching target film FL may be, for example, a spin-on-glass (SOG) film or a spin-on-carbon (SOC) film.

The metal-containing resist RM may be a resist film containing a metal. The metal-containing resist RM may contain at least one selected from the group consisting of tin (Sn), hafnium (Hf), and titanium (Ti). The metal-containing resist RM may contain, for example, at least one selected from the group consisting of tin oxide, hafnium oxide, and titanium oxide, or may contain an organic substance.

The metal-containing resist RM has a first region RMexposed to EUV light and a second region RMnot exposed to the EUV light.

First, in Step ST, as shown inor, the first substrate Was the substrate W is provided in the processing chamberof the heat treatment apparatus. The first substrate Wmay be transported into the processing chamber. The first substrate Wis provided on the substrate supportvia a lift pin. After the first substrate Wis disposed on the substrate support, the temperature of the substrate supportis adjusted to a set temperature. The temperature of the substrate supportmay be adjusted by controlling the output of one or more of the side wall heater, the stage heater, the ceiling heater, and the pipe heater(hereinafter, these heaters are also collectively referred to as a “heater group”). In the method MT, the temperature of the substrate supportmay be adjusted to the set temperature before the Step ST. That is, after the temperature of the substrate supportis adjusted to the set temperature, the first substrate Wmay be provided on the substrate support.

Subsequently, in Step ST, as shown in, the second region RMis removed by dry development using a development gas. Specifically, by exposing the first substrate Wto the development gas, the second region RMof the first substrate Wis selectively removed, and the metal-containing resist RM is developed. The development gas is supplied into the processing chamberby the gas supply. The supply of the development gas can be stopped at the end of Step ST. In Step ST, the first substrate Wmay be heated.

In Step ST, at least one development gas is supplied to the first substrate W. The development gas may contain at least one selected from the group consisting of hydrogen bromide (HBr), hydrogen fluoride (HF), hydrogen chloride (HCl), boron trichloride (BCl), an organic acid (for example, a carboxylic acid or an alcohol), and a β-dicarbonyl compound. The carboxylic acid in the development gas may include at least one selected from the group consisting of formic acid (HCOOH), acetic acid (CHCOOH), trichloroacetic acid (CClCOOH), monofluoroacetic acid (CFHCOOH), difluoroacetic acid (CFFCOOH), trifluoroacetic acid (CFCOOH), chloro-difluoroacetic acid (CClFCOOH), sulfur-containing acetic acid, thioacetic acid (CHCOSH), thioglycolic acid (HSCHCOOH), trifluoroacetic acid anhydride ((CFCO)O), and acetic acid anhydride ((CHCO)O). The alcohol in the development gas may include, for example, nonafluoro-tert-butyl alcohol ((CF)COH). The β-dicarbonyl compound in the development gas may be, for example, acetylacetone (CHC(O)CHC(O)CH), trichloroacetylacetone (CClC(O)CHC(O)CH), hexachloroacetylacetone (CClC(O)CHC(O)CCl), trifluoroacetylacetone (CFC(O)CHC(O)CH), or hexafluoroacetylacetone (HFAc, CFC(O)CHC(O)CF). In Step ST, the development may be performed by a thermal reaction between the development gas and the metal-containing resist RM. Alternatively, the development may be performed by a chemical reaction between chemical species in the plasma generated from the development gas and the metal-containing resist RM.

In Step ST, one or more of a plurality of development parameters may be changed. The plurality of development parameters include a temperature of the first substrate Wor the substrate support, a pressure in the processing chamber, a flow rate of the development gas, a type of the development gas, and a residence time of the development gas with respect to the first substrate W. One or more of these development parameters may be periodically changed. In an example, in Step ST, after the temperature of the substrate supportis set to a first temperature (for example, 10° C. or higher and 30° C. or lower), the temperature may be changed to a second temperature (for example, 40° C. or higher and 100° C. or lower) higher than the first temperature.

Step STmay be executed until the etching target film FL is exposed.is a view showing an example of a cross-sectional structure of the first substrate Wafter Step ST. In the example shown in, the second region RMof the metal-containing resist RM is removed, and an opening OP is formed. The opening OP is defined by side surfaces of the first region RM. The opening OP has a shape corresponding to the second region RM(consequently a shape corresponding to the exposure mask pattern used for the EUV exposure) in a plan view of the first substrate W. The shape may be, for example, a circle, an ellipse, a rectangle, or a shape obtained by combining one or more of these. A plurality of openings OP may be formed in the metal-containing resist RM. Each opening OP may have a line pattern or a hole pattern.

After Step ST, in Step ST, the first substrate Wmay be transported outside the processing chamberfrom a transport port of the first substrate W. Step STmay be included between Step STand Step ST. Since Step STis performed in a state where the first substrate Wis provided in the processing chamber, a first metal-containing substance MScan adhere to the surface of the first substrate W. In Step ST, the first substrate Wto which the first metal-containing substance MShas adhered may be transported.

In Step ST, Step ST, Step ST, and Step STmay be repeated. Step STmay be included between Step STand Step ST. By Step ST, the plurality of first substrates Wmay be sequentially subjected to dry development. Alternatively, in a case where the dry development is performed on one first substrate W, Step STmay not be performed.

After Step ST, in Step ST, as shown in, the second substrate Wdifferent from the first substrate Wmay be transported into the processing chamber. The second substrate Wmay be a cleaning substrate (dummy wafer). In Step STand Step STto Step ST, for example, the substrate may be carried in and carried out by a transport robot.

By the dry development in Step ST, the first metal-containing substance MScan adhere to the processing chamberor the component disposed in the processing chamber, as shown in.is a partially enlarged cross-sectional view of an example of the substrate processing apparatus after Step ST. The first metal-containing substance MScan coat the inner surface of the processing chamber, and the surfaces of the ring assemblyand the substrate support. The first metal-containing substance MScan contain the same metal as the metal contained in the metal-containing resist RM. The first metal-containing substance MSmay contain at least one selected from the group consisting of tin (Sn), hafnium (Hf), and titanium (Ti). The first metal-containing substance MSmay contain at least one selected from the group consisting of tin oxide, hafnium oxide, and titanium oxide.

In Step ST, the first metal-containing substance MSadhered to the processing chamber, the ring assembly, and the substrate supportis removed. Step STmay be performed in a state in which the second substrate Wis disposed on the substrate support. Step STincludes Step STand Step STafter Step ST.